Here is the full list of all 28 Vampyr achievements. It takes around 35-40 hours to unlock all of the achievements on Windows.
Turn a district to hostile status
Defeat Mary
Take care of Sean's fate
Defeat Fergal
Eat 10 rats
Take care of Dorothy's fate
Heal 10 citizens
Upgrade a weapon with a module
Upgrade a weapon
Let Clay live during your first meeting with him
Take a ride with Doctor Swansea
Go to the Shelter and rest …
Embrace Clay during your first meeting with him
Save this poor plant with water
Find all melee weapons
Find all ranged weapons
Find all off-hand weapons
Find the recollection of Paulus Aurelianus
Gather all collectibles
Upgrade a weapon to level 5
Take care of Aloysius's fate
Take care of Swansea's fate
Complete the game
Finish the game without killing any citizens
Defeat Doris
Defeat McCullum
Defeat The Disaster
Turn all districts to hostile status